Electrolytic production of magnesium.



UNI D STATES PATENT onnron.

GEORGE O. SEWARD AND FRANZ VON KI IGELGEN, OF HOLCOMBS ROCK, VIRGINIA,ASSIGNORS TO VIRGINIALABORATORY COMPANY, OF NEW YORK, N. Y., ACORPORATION OF NEW YORK.

ELECTROLYTIC PRODUCTION OF MAGNEsIUM.

To all whom it may concern:

Be it known that we, GEORGE O. SEWARD, a citizen of the United States,and FRANZ you KIB'GELGEN, a subject of the German Emperor, both residingat Holcombs Rock, in the county of Bedford and State of Virginia, havejointly invented certain new and useful Improvements in the ElectrolyticPro- I duction of Magnesium, of which the 'following is a specification.

This invention relates to the roduction of magnesium by electrol sis 0its fused salts. Such electrolysis a ords serious difficulty, becausethe difference in the specific gravity of the liberated metal difi'ersso slightly from that of its fused salt, that the metal does not readilyseparate. It is practically necessary for good results to use anelectrol te whose specific gravity is so different rom that ofmagnesium, that the-latter will either sink readily to the bottom orrise freely to the to of the bath, where it canbe collected. Kbr a metalas light as magnesium it is extremely diflicult to find electrolyteswhich have so .low a specific gravity that the separated metal willreadily sink tothe bottom, and insuch cases it is A trolytically from anelectro preferable to add to the electrolyte a component' which willmake it materially heavier than the metal, so that the latter will riseto the top of the bath. Such added component should be a flux which iseflicient when used in comparatively small quantities, and should not bedecomposed by the current.

The present invention is characterized by the use for this purpose ofthe salts of the alkali-earth metals, which are peculiarly suited tothis use because (1) they have a high specific gravity, and (2) they aredifficult .to decom ose electrolyt1cally.' I

As an examp e of the practical application of our invention, we willdescribe the production of magnesium b electrol sis of magnesiumchlorid, using arium c orid to increase the specific gravity of theelectrolyte. m r

At present magnesium -is produced elecyte of fused Specification ofLettersPatent. Application filed larch 28, 1906. Serial No. 308,454.

'perature that such an electrolyte is lighter Patented Aug. 17, 1909.

magnesium chlorid, with potassium chlorid added as a flux, the separatedmagnesium being collected at the bottom of the vesse1 It is only undercertain conditions of temthan the separated magnesium, and it isdifficult to so manage the process that these temperature conditions aremaintained so that a good separation of the magnesium re-' sults.

In producing magnesium according to the present invention, we replacethepotassium chlorid partly by barium chlorid, so that we obtain anelectrolyte which is so much heavier than the magnesium, that the latterrises readily to the top, where 1t ma be collected. Although the'roportion. 0 barium chlorid may be great y varied, we have found anelectrolyte of the followin composition to give suitable results gOl, 5parts, KGl 5 parts, BaCl 3.5 parts.

Instead of barium chlorid we may use the chlorid or other suitable saltof calcium or strontium.

We are aware that alkali-earth salts have been used before as fluxes,"but not for the purpose of regulating the specific gravity of theelectroyl What we claim is v 1. The electrolytic production of magnesiumby electrolyzing fused magnesium chlorid to which is added enough of adenser alkali-earth chlorid to ren er the bath heavier than theseparated ma esium.

2. The electrolytic production of magnesium by electrolyzing a fusedbath of magnesium chlorid and barium chlorid.

3. The electrolytic production of magnesium by electrolyzing a fusedbath of mag;

nesium chlorid, potassium chlorid, an barium chlorid.

In witness whereof, we have hereunto scribing witnesses.

- GEORGE O. SEWARD.

FRANZ VON -KUGELGEN. Witnesses:

J. H. WEBB,

F. V. Bmnnn.

